Implementing COMMIT frequency

Question

I've been asked to create a procedure which should delete from a table records which are older than a specified period(input parameter) with a User specified Commit Frequency(This will be another Input parameter)
I have a column called created_time in mytable which i could use in WHERE clause of the DELETE statement.
create or replace procedure delete_mytable
       p_commitfreq  in number
       p_no_of_days_old in number
as
begin
DELETE FROM mytable where created_time< sysdate-p_no_of_days_old;
-- code to implement COMMIT frequency
end;
How can i implement COMMIT frequency in this proc?. Client is going to COMMIT after every 35000 rows. But they don't want this to be hard coded. I have seen other threads in OTN where Gurus are saying that including COMMIT frequency is a bad thing. This just happens to be in SPECS which I don't get to design(we are actually converting a Purge script written in C++ to PL/SQL)

Answer 1

I have seen other threads in OTN where Gurus are saying that including COMMIT
frequency is a bad thing. We consider the use of COMMIT in the middle of a business transaction to be bad practice for a number of reasons:
(1) Multiple commits are generally slower.
(2) It is frequently associated with an implementation which consists of record-by-record processing inside a PL/SQL curosr loop when set-based processing is far more efficient.
(3) It can be harder to recover from a failed business transaction if the data is in an inconsistent state.
(4) Such implementations are prone to ORA-01002 and ORA-01555 errors.
Now the question which occurs to me in your case is, "Why do you users care?" In fact, would they even notice if you implemented the procedure as you show in your post and just ignore the p_commitfreq?
However, if your conscience won't let you do that, the best solution would be something like this:
  << commit_loop >>.
  loop
       delete from mytable
       where created_time< sysdate-p_no_of_days_old
       and rownum <= p_commitfreq;
       exit when sql%rowcount = 0;
      commit;
  end loop commit_loop;
  commit;This solution will be slower than a single commit approach but avoids the other issues.
Cheers, APC
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